Rawalpindi vs urban center

Rawalpindi and urban center both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rawalpindi	Yes	No	No	No
urban center	Yes	No	No	No

Rawalpindi (noun)	urban center (noun)
an ancient city in northeastern Pakistan; served as capital of Pakistan while Islamabad was being built	a large and densely populated urban area; may include several independent administrative districts